Sound-absorbing unit and method of making the same



May 21, 1935; I .1. MAZER 2,001,

SOUND ABSORBING UNIT AND METHOD OF MAKING THE SAME Filed Oct. 25, 1930 INVENTOR Patented May 21, 1935 UNITED STATES PATENT OFFICE My invention relates to sound-absorbing units and a method of SOUND-ABSORBING Um AND METHOD OF MAKING THE SAME Jacob Marci, Stonehurst, Upper Darby Township,

' Delaware County, Pa.

Application October 25, 1930, Serlal No. 491,151

6 Claims. (01. 154-28) making the same, and more particularly to materials such as are employed inthe walls and ceihngs of auditoriums, studios,

etc., for definitely absorbing and controlling re.-

verberation of sound waves. Various plans have heretofore been adopted for controlling and absorbing sound waves, such as porous masonry materials, fibrous'bodies, rigid cellular panels, etc.

These various materials have been open to obiections such as the necessity of forming them at the place of installation, and in conjunction with the walls or ceilings to be covered, as in the case of plastic or fragile nature of readily subject to which are subject son of the elasticity,

masonry materials; the the fibrous bodies which are damage through handling and to natural limitations by reasize, etc.', of various vegetable fibers, hair, etc., and the difliculty of applying pre-formed cellular units to spaces of various areas and contours.

Further, in the case with exposed apert of divisi various decorative of the rigid cellular bodies effects.

One object of my invention is to provide soundabsorbing units which are highly flexible so that they will yield under the impacts of sound waves and which can be conveniently handled and installed.

and wherein there are no clear lines of division or spaces either on the surface of an individual unit or between assembled Still another object of vide a sound-absorbing body units.

my invention is to prothat may be formed or various materials including materials which are nonecombustible highly emc'ient to tions of sound waves.

and which is nevertheless absorb and control reverbera- Some of the forms which my invention may take are shown in the accompanying drawing wherein Figure absorbing unit similar view but ment of' the fibres; Fig. lcation; Fig. 4 is a view ,1 is a perspective view of a soundcontaining fine fibres; Fig. 2 is a showing a modified arrange- 3 shows another modisimilar to 3, but

showing the appearance presented by the surface of a plurality of unitsassembled, of the character as shown in Fig. 3, and Fig. ti shows another manner in which may be formed.

units similar"to*that of Fig. 3

, table,

such apertures and lines on are too clearly visible to permit of Referring to Fig. 1, I show a unit having a backing sheet or base I to which the ends offibres I may be secured by cement or otherwise. The backing sheet 6 may be of any suitable material such as a fibrous body or a metallic sheet, and is preferably flexible so that it can be readily bent to the contour of a wall surface to which the-unit is applied. The fibres I may be vegeanimal or mineral, as may be desired. These fibres are placed perpendicular to the backing sheet with their inner ends secured thereto so that they will have great yieidability or flexibility and thus be extremely sensitive to sound waves. i

Obviously, the yieidability will be greater by reason of their perpendicular arrangement than if they were arranged in mat-like or woven relation. Metallic or asbestos fibres will of course be employed where a structure that is fireproof and vermin-proof is desired. The exposed surface of the units can be brushed to produce a uniformlystippled effect and to break up visible lines of division between adjacent units and can be given a decorative facing of point or thin plaster, if desired... 2 r v In Fig. 2, I show a structure which, on its exposed surface, presents the appearance of Fig. '1, but wherein the fibres instead of being uniformly distributed over the backing sheet 8 are arranged in small groups or bunches, with their outer ends brushed. or pressed inward slightly to provide a substantially unbroken appearance at the surface 4 of the unit.

In Fig. 3, I show a unit formed of a block of yieldable material which may be of a fibrous body such as asbestos. The block is cut or slitted in various directions so as to produce the effect of perpendicularly-arranged fibres 9 corresponding to the fibres l of Fig, 1, but which are coarser. The cuts are not made entirely through the block but a portion l0 thereof is left unslitted so as to serve as a backing sheet or base for the'fibre-like projections 9, and the base It may lnturnbesecuredto'asheetll.

The exposed ends of the strand-like members 9 an: fiziifed by brushing or compressing them in a direction perpendicular to the plane of the unit, so as to produce an exposed surface that is of mat-like appearance without pronounced lines of division between the strands of each unit or the strands of adiacent units, as shown in Fig. 4.

Fig. 5 shows a unit which when completed is similar to the units of Figs. 3 and 4, but wherein a morecompact arrangement of the perpendicu- V somewhat in a fringe-like manner as shown in Figs. 3 to 5, the material is preferably an inherently yield-; ing nature such as asbestos so that the unit will have the requiredflexibility or yieldability, while in the case of finer fibres these may be of various materials, including a metal, such as copper, lead. certain alloys, of the spreading or flufiing of the ends thereof so as to produce the efiect of a homogeneous mass at the exposed surface of the unit.

In the case of asbestos fibres or similar material, if they be first wet, their ends canbe spread more easily by a fiufiing or wiping action than if they are dry. Also, a smooth exterior can be provided on the unit by the use of wetted lime or plaster, which may be wiped or spread across the ends of the fibres, as shown at I3 in Fig. 4.

The term perpendicular herein is not employed in its strict technical sense, but includes also fibres, etc., which extend in a generally outward direction.

I claim as my invention;

1. A sound-absorbinglunit comprising a block of material slitted in directions perpendicular to the plane thereof to form outstanding strands,

the block being of a material which is deformable to permit fiufiing of the outer ends of the strands and thus present a substantially unbroken appearance.

2. The method of forming sound-absorbing .units which comprises making numerous slits in ablock of material perpendicular to the plane exposed surface that has'the appearance of being unperforated. v

3. The method a forming sound-absorbing units which comp as cutting a series of slits in a strip of material from one edge thereof to a point adiacent to its opposite edge and folding the said strip upon itself to produce a block-like etc. The soitermetal will permit body 4. The method of forming sound-absorbing units which comprises cutting aseries of slits in a strip of material from one edge thereof to a point adjacent'\ to its opposite edge and folding the said strip .uton itself to produce a block-like body, and fiufiingthe outer ends of the slit portions to conceal the slits.

I 5.'-A sound-absorbing body comprising elements each consisting of a homogeneous mass of matted fibrous material, extending generally perpendicularly to the plane of the body and dis-' posed in side-by-side relation, ends enlarged in directions parallel to the plane of the unit.

6. A sound-absorbing body comprising elements-of homogeneous ductile material extending generally perpendicularly to the plane of the body and disposed in side by-side relation, with their outer ends enlarged in directions parallel to the plane of the unit. JACOB MAZER.

with their outer. 

